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confirmation about battery charging

Posted: Tue Dec 06, 2022 3:38 pm
by smoked_salt
Hi All,

Just had a new solar install
1 x H1-3.7-E Inverter
2 x HV25 batteries
10 x 400w array.

there have been a few teething issues with CT meters, but I believe anything is generating/reporting as it should.

Have also set up homeassistance with MODBUS, everyone loves data! :D

I have questions about the battery charging, the supplier hasnt really been forthcoming with information...

The SOC has been set to 10% by the installers as per documentation. As there is not much PV generation at the moment the batteries arent reaching a full charge, rarely exceeding 30%. After a while the house load uses the battery and they discharge to 10% and begin charging from the grid.
This picture shows the SOC and Grid consumption over night, i think a graph gets the point across much better than I can convey.
battery_SOC.png
I take it draining to 10 % and then charging a little from the grid and repeating this process (11 times is what I count in the graph)doesnt cause harm to battery and this is indeed how it is intended to work? or should i be expected to get the batteries upto 100% before using again?


Next questions rolled into one topic...
We had a sunny day with no clouds, and I was producing approx 2.2KW !!!!! when looking at the graphs it showed my batteries charge maxing out at 1KW, then the rest going to the grid/house load
graph.png
.
My batteries and inverter are installed in the garage, could the limit of 1kw charging be limited to the temperature? similar thing mentioned in this post viewtopic.php?t=71. I see an ambient temperature displayed in HA which displays around 15C, but the temp in the garage is around 8C according to a seperate thermometer.
Or could the limit be because I only have 2 batteries, as mentioned in Wills post at Sat Nov 05, 2022 11:23 am in viewtopic.php?p=156#p156.

Or even a mixture of both cold and batteries numbers?

Im sure there will be lots more questions to be asked in the future but lets just stick to batteries at the moment :)

Re: confirmation about battery charging

Posted: Sun Jan 08, 2023 10:48 pm
by SolarJunkie
Solar energy use controlled by your system will be prioritised.
Most likely it will be house loads, battery and then grid, in that order.
The house house will take what it needs and the rest will go to charge the batteries, so unless the house is drawing no load at all, the battery charging power will always be less than that generated by the solar panels.

Edit: I’ve re-read your post and it does look like the battery charging is clipped for some reason.

Re: confirmation about battery charging

Posted: Mon Jan 09, 2023 10:03 pm
by cutlea01
Something not right there. You shouldn't be recharging from the grid during the day. Day discharge if there's no solar and recharge during the small hours on cheap rate, else there's no point recharging at all from the grid.

Re: confirmation about battery charging

Posted: Fri Jan 20, 2023 11:48 am
by Megadethmaniac
I seem to be having the same issue.

Currently charging at 1-7-2kwh in the sun battery charging just over 1kw load 350w and experting the balance.

Some suggestion of clipping what is this and can we unclip?

Re: confirmation about battery charging

Posted: Thu Feb 02, 2023 2:29 pm
by gumpster1981
Try a force charge from the grid for an hour to see if the battery will take a full load charge then, depending on whic inverter you have this will be limited to either 3.68kw or 5.0kw. The only other thing is what kind of ambient temps you had at the times when it was limiting charge rate and exporting to the grid as this will effect the batteries, I had this on my system when we had below 0deg temps before Christmas, the batteries BMS will limit the charge amd discharge rate to protect the batteries.